How do you pronounce "schedule"?

[Vasher]

Aluminum.

Obviously, you're missing an "i" there, just after the "n". Whether or not one chooses to pronounce it is dependent upon which variety of English you're speaking, as leaving the second "i" silent is standard in American English and some other varieties, but I will not waver when it comes to spelling. With spelling, there is a right way and there are wrong ways.

The first printed reference to "Aluminum" is in Sir Humphrey Davy's "Elements of Chemical Philosophy" (1812) which describes his experiments with "Aluminum". It was later changed by the Brits to conform with other elements that end with "ium". It was originally spelled "Aluminum", coined by Davy using Latin "alumen" and "alum". So, the original spelling is "Aluminum".

Au contraire! The Oxford English Dictionary is very clear that there is a printed reference to "aluminium" in 1811, as reproduced below. However, it is worth noting that this refers to aluminium as a theoretical substance.

~1811 Crit. Rev. Jan. 9 The result of this experiment is not wholly decisive as to the existence of what might be called aluminium and glucinium.

You "cherry picked" from a Reddit post;

"And yet, the Oxford English Dictionary itself lists the first use from 1811 Crit. Rev. Jan. 9 The result of this experiment is not wholly decisive as to the existence of what might be called aluminium and glucinium.

The same dictionary entry bears the note Quot. 1811 at sense A. 1 is a review of a lecture by H. Davy delivered in 1809 and published in 1810 ( Philos. Trans. (Royal Soc.) 100 16–74). The published paper, on which the review appears to be based, does not name the new substance created by the experiments described; the ingredient alumina is referred to in the form alumine (see alumine n.)."

It's "Aluminum".